The Electrical Conductivity Structure of the Lanping–Simao Basin and its Implications for Mineralization

Objective The Lanping-Simao Basin in western Yunnan, located in the southeastern margin of the Tibetan Plateau, is tectonically in the transition zone between the Gondwana and Eurasia tectonic domains. It is also the frontier zone of northeastern extrusion of the Indochina Plate towards the Eurasia Plate as well as the escape zone for the deep material. The middle axial tectonic zone, also known as the Lanping-Simao Fault （LSF） in previous study, is a giant intraplate tectonic belt composed of a series of narrow uplift belt, rupture depression zone, metamorphic belt, alteration belt and marginal fracture system, which were formed by the compressional uplift of the central depression of the Lanping-Simao Basin. This tectonic unit controls the geological evolution, seismic activity, hot spring distribution and ore formation of the LanpingSimao Basin since the Mesozoic and Cenozoic.

STUDIES ON THE ELECTRICAL CONDUCTIVITY OF FREE-STANDING FILMS OF POLYANILINE

An insulate to metal transition was investigated based on the measurements of the dependence of the conductivity, activation energy on the protonation state of polyaniline (PANI). An isotropy in conductivity for stretched salt form of PANI was observed.For salt film of PANI, the Ⅰ-Ⅴ curve obeys Ohm's law, which shows a typical metal behavior, however, for base film or film with low protonation state, it can be explained by Space Charge Limited Current (SCLC). It is also found that the Ⅰ-Ⅴ curve of base film of PANI is independent of the work function of electrodes and the polymerization temperature.

Optical,UV-Vis spectroscopy studies,electrical and dielectric properties of transition metal-based of the novel organic–inorganic hybrid(C_(6)H_(10)N_(2))(Hg_(2)Cl_(5))_(2)·3H_(2)O

In this work,we are interested in the synthesis of new hybrid material(C_(6)H_(10)N_(2))(Hg_(2)Cl_(5))_(2)·3H_(2)O grown by hydrothermal methods.X-ray diffraction indicates that this compound crystallizes at 150(2)K in the monoclinic system with C2/c space group,with the following unit cell parameters:a=19:6830(15)Å,b=18:1870(15)Å,c=6:8567(6)Å,β=93:224ð3Þ○and Z=4.On the other hand,the optical properties of this compound were studied using ultraviolet-visible(UV-Vis)spectroscopy in the range 200-800 nm.Furthermore,the optical absorbances are used to determine the absorption coefficientαand the optical band gap E g,so the Tauc model was used to determine the optical gap energy of the compound(C_(6)H_(10)N_(2))(Hg_(2)Cl_(5))_(2)·3H_(2)O.The analysis of the results revealed the existence of optical allowed indirect transition mechanisms with the band gap energy equal to(2.37 eV)for liquid and(4.33 eV)for solid.Impedance measurements indicate that the electrical and dielectric properties are strongly dependent on both temperature and frequency.Nyquist plots(Z'' versus Z ')show that the conductivity behavior is accurately represented by an equivalent circuit model which consists of a series combination of bulk and grain boundary.Furthermore,the angular frequency dependence plots of the real and imaginary parts,ε' andε'',of complex dielectric permittivityε*and tanδlosses at several temperatures between 303 and 453 K were studied for the title compound.Finally,the modulus plots can be characterized by the presence of two relaxation peaks.

ELECTRONIC ENERGY BAND STRUCTURE OF MOLECULAR CRYSTALS MCI·(TCNQ)_2 AND ITS RELATIONSHIP WITH THE ELECTRICAL CONDUCTION

The structure of electronic energy bands, electric charge distribution and the amount of charge transfer of molecular crystals 1-MCI·(TCNQ)_2 (Ⅰ) and 2-MCI· (TCNQ)_2 (Ⅱ) have been studied. The results are: (ⅰ) The dominant contributions to the electrical conductivities for crystals Ⅰ and Ⅱ are from TCNQ molecular columns, and the charge carriers are electrons. (ⅱ) The electrical conduction is mainly due to the hopping of charge carriers between the seats of lattice. (ⅲ) The considerable difference of the electrical conductivities between crystals Ⅰ and Ⅱ is due to the differences between (a) the concentrations of charge carriers n_(AⅠ)~C= 0.9988-|e|/cell and n_(AⅡ)~C=0.0340-|e|/cell; (b) the widths of the energy bands △E_(AⅠ)^(LU)=0.88 eV and △E_(AⅡ)~LU=0.040 eV; (c) the first derivative of E with respect to k, (dE/dk)_(K_FAⅠ)^(LU)=0.27 eV· and (dE/dk)_(K_FAⅡ)~LU=0.0048 eV·; and (d) the difference of energy barriers for the hopping of charge carriers ∈_Ⅱ-∈Ⅰ=2.5-8.8 kJ/mol.